This proposal describes methods for the efficient and controlled bioconjugation and self-assembly of carbon nanotubes (CNTs). The proposed research will focus on the development of mild chemical methods for the covalent attachment of biomolecules (nucleic acids, proteins, carbohydrates, etc.) and small molecules with solubilizing properties to carbon nanotubes and their self-assembly into new hybrid materials. These hybrid DNA-CNT materials will be characterized and their molecular recognition properties explored for use as electrochemical or field-effect-transistor based biosensors. The first aim of the proposal is the development of methods for the functionalization of carbon nanotubes with biomolecules (DMA). The second aim of the proposal is the development of new DMA-based carbon nanotube assembly techniques. The last aim is to study the enzymatic modification and molecular recognition properties of these new materials with proteins and small molecules, paving the way toward their application as highly sensitive biosensor systems. The three primary architectural strategies for assembling DMA materials are linear, branching, and multibranched higher order motifs. The linear strategy is the simplest conceptually, and has been applied recently to the self-assembly of gold nanoparticles into highly ordered crystalline arrays. While this strategy has been demonstrated for gold nanoparticles, the self assembly of DNA-carbon nanotube materials, with high degrees of order, has yet to be achieved and represents a much needed area of research. The successful self-assembly of DNA-carbon nanotube conjugates into highly ordered materials would constitute a major advance in the field and is the principle goal of the proposed research. The discovery of novel biomaterials and detailed knowledge of their fundamental properties could lead to practical applications in human health and medicine. DNA-CNT hybrid materials have many potential applications some of which include substrates for cell growth or tissue regeneration, drug delivery systems, gene transfection reagents, nanotube (non-viral) mediated oligonucleotide transport for siRNA, and electrochemical or field-effect-transistor based biosensors.